This is one of the easier large-scale canvas projects you can do yourself. I love Sailrite, but there are less expensive sources and methods for almost everything they sell.
The easiest way to get a snap installed in fabric where it needs to be is to hold it where it needs to go with spring clamps, double sided tape, or temporarily with your hands, and use a chalk pencil to find the center of the snap and mark it from the other side. The sailrite system is certainly a little more convenient and accurate, but also has some drawbacks: Namely you're putting a hole through your material even if you haven't finalized the tension or location.
Probably more than you want to know, but the general process I used with some tips:
- Sew two lengths of canvas together length wise, oversized with your preferred seam. There's no need to pattern this because the center section pretty much has to be this shape/construction.
- Use double sided tape on top of strapping tape to hold your new center section fore and aft on the boat, from the cabin top to wherever it will attach aft. Use clamps if there's anything that is pulling too hard.
- Rough cut the center section as needed; I like to keep everything as oversized as possible until it starts getting in the way or needs to go.
- Use scrim fabric to pattern the triangle-shaped sides. I really like the Sailrite fiber reinforced stuff (available from masonry/construction supply houses for less if you can buy a lot of it) but you can also use cheap house wrap. Use the same double sided tape on strapping tape technique.
- Sew together the side panels.
- After you have everything sewn together rough and the general shape, you'll have to add any darts, as well as reinforcing or chafe patches. If you've used lightweight material, you will definitely want reinforcement everywhere a snap might be installed. You can pre-plan all this stuff for a potentially nicer looking result.
- Wait as long as you can to add snaps and add them incrementally to double check the fit. This is a lot easier if you are using a Pres-n-Snap tool or similar.
- Cut your outer edges fair in a manner that will work with your binding and binder.
- Use binding to finish the edges; you don't have to use expensive Sunbrella Binding, there are lots of less expensive products sold as lightweight webbing that will feed into a binder and work great.
This is probably obvious, but: Depending on your construction, you might wind up with some very thick seams to step over. Make sure your machine can handle that. You also might wind up with a very heavy assembly that will try to deflect your needle. Working on the floor is my preference if you have a portable machine.
Good luck and show us the results!
